Spindle bolster

ABSTRACT

A spindle bolster assembly of the type wherein a spindle blade is resiliently mounted in a bolster case for lateral movement of its lower end with a footstep bearing to minimize vibrational stresses. The footstep bearing is resiliently biased to a centered position by a centering spring anchored to the lower end of the bolster case which additionally axially locates and prevents rotation of the footstep bearing.

[451 Mar. 19, 1974 3,065,593 11/1962 Westall et 3.100.375 8/1963 Bourgeas 3,298,757 1/1967 FOREIGN PATENTSOR APPLICATIONS 952,177 3/1964 Great Britain........................

1,075 0/1905 Great Britain......

Primary ExaminerJohn Petrakes Attorney, Agent, or Firm--McNenny, Farrington, Pearne & Gordon [57] ABSTRACT A spindle bolster assembly of the type wherein a spindle blade is resiliently mounted in a bolster case for lateral movement of its lower end with a footstep bearing to minimize vibrational stresses. The footstep bearing is resiliently biased to a centered position by a SPINDLE BOLSTER Inventors: John P. Kieronskl, Charlotte, NC;

Ray C. Johnson, Holden, Mass.

Assignee: Whitin Machine Works, Inc.,

Charlotte, NC.

Mar. 1, 1972 Appl. No.: 230,603

57/135, 308/152, 308/155 Int. D0111 7/12 Field of Search....... 57/89, 132, 134, 135, 129, 57/130; 308/145, 152, 155, 156, 157, 228

References Cited UNITED STATES PATENTS Unite States Patent 1 1 Kieronski et a1.

[22] Filed:

52] U.S.C1........

centering spring anchored to the lower end of the bolster case which additionally axially locates and prevents i'otation of the footstep bearing. 57/ 132 222 555 ill. 8800 000 333 a 0L uue m n. u flk uwfln wmm TJKWM 39534 88955 880099 11111 69 96 1 44759 77265 ,97 90900 7 458 245 96 22 5 Claims, 4 Drawing Figures SPINDLE BOLSTER BACKGROUND OF THE INVENTION The invention relates to improvements in textile spindle assemblies and in particular to apparatus of the type in which the spindle blade is resiliently mounted to minimize vibrational stresses in the blade and associated structure,

Textile spindles in spinning and doubling frames are operated at extremely high speeds, in the order of up to 15,000 r.p.m. As a yarn package is built up on the bobbin mounted on the spindle, an unbalance of the mass of the yarn with respect to the axis of the spindle is generally unavoidable. Even a slight unbalance is a potential source of high vibrational force owing to the high rotational speed. It is generally recognized that vibrational stresses in the spindle blade and support bearings may be minimized if the spindle blade is resiliently mounted in a rigid bolster.

In a known type of spindle mounting arrangement and in the preferred embodiment of the present invention, the spindle blade is mounted with its midportion journaled in a fixed radial bearing while its lower end is supported in a resiliently mounted footstep bearing. In such an arrangement, the radial bearing provides a fulcrum or pivot point about which the spindle blade may oscillate laterally under the influence of centrifugal forces developed by an unbalance in the spindle. Such forces are resisted and damped by damping and centering means operating on the lower footstep bearing which is laterally displaced with the lower end of the spindle blade.

SUMMARY OF THE INVENTION The invention relates to improvements in mounting of the footstep bearing in a spindle bolster wherein vibration induced lateral displacement of the footstep bearing is precisely controlled by centering spring means resiliently biasing the footstep bearing to a centered or ideal position. Besides its principal function of centering the footstep bearing and spindle blade, the

centering spring means vertically supports the footstep bearing and spindle blade. Additionally, the spring means functions to prevent rotation of the footstep bearing.

In the illustrated embodiment, the spindle bolster includes a rigid tube in the upper end of which a radial bearing is fixed. A spindle blade is journaled in this radial bearing and extends downwardly into the bolster tube to a footstep bearing. The blade is both radially and axially supported for rotation in the footstep bearing. A centering spring is anchored at one of its ends in a lower end wall of the bolster tube and at its other end in the footstep bearing. This arrangement permits the spring to resiliently resist lateral deflection of the footstep bearing from a centered position relative to the bolster tube.

The spring is dimensioned to vertically support the footstep bearing at a desired axial position in the bolster tube and to provide torsional resistance to prevent rotation of the footstep bearing relative to the bolster tube. Spacer means for limiting axial movement of the footstep bearing from the desired axial position protects the spring from damage such as when a spindle blade is dropped with force into the bolster tube. A further feature provided by the centering spring is axial restraint of the footstep bearing preventing it from BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal section view of a spindle bolster assembly embodying the principles of the inventron.

FIG. 2 is a fragmentary sectional view illustrating details of a portion of the bolster assembly illustrated in FIG. 1 on a somewhat enlarged scale showing details of the mounting of the footstep bearing.

FIG. 3 is a fragmentary sectional view, similar to FIG. 2, illustrating details of another embodiment of a mounting and spring arrangement for the footstep bearing.

FIG. 4 is a fragmentary sectional view, similar to FIGS. 2 and 3, showing another embodiment of the spring centering means for the footstep bearing.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1, there is illustrated a spindle bolster assembly 10 which includes a cylindrical tubular bolster case 11. External threads 12 adjacent an upper end 13 of the case 11 along with a compatibly threaded nut (not shown) provide means for rigidly mounting the bolster tube 1 1 on a rail of a conventional spinning or doubling frame. In a known manner, the bolster assembly 10 is clamped on the rail by gripping the latter between an internally threaded flange 14 and the threaded nut. An upstanding projection 16 integral with the flange 14 supports a doffer latch 17 pivotal on a pin 18.

A conventional spindle blade 21 having a cylindrical portion 22 and a tapered end portion 23 is journaled in the bolster case 11 by means of an upper radial bearing 26 and a lower footstep bearing 27. As illustrated, the upper radial bearing 26.is of the roller bearing type and is retained in a counterbore 29 in the upper end 13 of the bolster case by a press fit. The outer surface of the cylindrical portion 22 of the spindle blade 21 thus forms an inner race for the rollers, designated 30, of the radial bearing 26. Alternatively, if desired, the radial bearing may be constructed to be retained on the blade 21 for removal therewith from the bolster base 11. In this case, the fit between the bearing and the counterbore 29 is free enough to permit ready removal of the bearing with the blade 21. From the radial bearing 26, the cylindrical portion 22 of the blade extends axially through a first cylindrical bore 31 in the case 11.

Adjacent a lower end 33 of the case 11 there is provided a second axial cylindrical bore 34. Positioned in this'cylindrical bore 34 is a damping spring 36 of well known construction which comprises a plurality of precisely formed helical coils having capillary like spaces 37 (FIGS. 2-4) therebetween. A coil forming the outer diameter of the spring 36 engages the wall of the associated bore 34 while a coil forming the inner diameter of the spring engages an outer cylindrical surface 38 of the footstep bearing 27. The coils of the damping spring 36 are capable of moving laterally or eccentrically of the bolster axis to accommodate lateral movement of the footstep bearing 27. A tapered bore 41 having an included angle slightl greater than that of the tapered portion 23 of the spindle blade 21 is provided in the upper end of the footstep bearing 27 for reception therein of the blade. At

a lower end of the tapered bore 41 there is provided a generally conical seat or bearing area 43 on which a compatibly shaped conical blade end 44 is vertically and laterally supported. A radial hold 46 and an axial groove 47 on the exterior of the footstep bearing 27 provide passage for lubricating oil to the bearing seat 43.

A cylindrical counterbore 51 in the lower end 33 of the bolster case 11 terminates at a radial shoulder 52 adjacent the bore 34. A cylindrical plug or end wall 53 is positioned in the counterbore 51 against the shoulder 52 and held in position by spin rolling an edge 54 of the case 11 against the plug. A conventional elastomeric O-ring seal 56 on the plug 53 prevents leakage of oil from the interior of the case 11.

In the first embodiment of the invention illustrated in FIGS. 1 and 2, and with particular reference to the latter Figure, the footstep bearing 27 is centered with respect to a longitudinal axis defined by the bolster case 11 by means of a substantially straight resilient spring or pin 71. Preferably, the pin 71 is round and is centered on the axis of the bolster case 11 by mounting one of its ends 72 in a blind axial hole 73 drilled in the plug 53. At its other end 74, the pin 71, ideally, is mounted in a cylindrical tubular bushing 75. The pin 71 is preferably made of a high strength material such as music wire and is knurled at each of its ends 72 and 74 to maximize the grip of surrounding material when such ends are press fitted into the plug 53 and bushing 75.

Normally, the footstep bearing is formed of relatively hard material such as a heat treated tool steel to provide satisfactory wear resistance against frictional contact with the spindle blade 21. It has been found that the hardness of the footstep bearing 27 may be enough to destroy the knurled edges of the pin 71 when the pin is pressed into a suitable hole in the footstep bearing. Use of a relatively softer material in the bushing 75 avoids this problem. Preferably, with the end 74 of the spring in the bushing 75 and before these members are assembled in the bolster case the bushing is subjected to a heavy compressive load in a blind axial bore 76 sufficient to cause the bushing 75 to be plastically deformed. Upon removal of the deforming load the residual compressive stress in the bushing will be at a maximum to insure that the pin end 74 will be permanently retained therein.

Spacer means in the form of a tubular cylindrical bushing 78 is dimensioned with an axial length slightly less than the axial spacing between the plug 53 and footstep bearing 27. The rigid spacer 78 is provided to protect the centering spring 71 from excessive column loads which would cause it to buckle plastically such as when the spindle blade is dropped into the footstep bearing with usual force. Preferably, the outside diameter of the spacer 78 is substantially equal to that of the footstep bearing 27. The resulting axial clearance between the spacer 78 and footstep bearing 27 normally permits the footstep bearing to shift laterally or radially with respect to the longitudinal axis of the bolster case 11 without frictional contact between the spacer and bearing. However, if an excessive axial load is applied to the footstep bearing 27 as might occur if a spindle is forced downwardly into the bolster, the pin 71 will bend or deflect laterally only until the bottom of the footstep bearing 27 contacts the upper surface of the spacer 78 to thereby limit the axial loads applied to the centering spring 71.

In a conventional manner of operation, the spindle i blade 21 is rotated relative to the bolster case 11 by a drive belt (not shown) engaging a whorl 81, shown in phantom, telescoped over the upper end 13 of the case 11. The whorl 81 in a typical manner is fixed to the spindle blade 21 by means (not shown) above the radial bearing 26. Normally, the interior of the bolster case 11 will be filled with a suitable lubricant or oil to a point approximately midway along the length of the cylindrical portion 22 of the blade 21. This oil serves both to lubricate the contacting surfaces of the blade 21 and footstep bearing 27, in particular, the bearing seat 43 and blade end 44, and to fill the spaces 37 between the coils of the spring 36.

The spindle blade 22 extends above the radial bearing 26 to a sheath (not shown) on which a tube may be positioned for winding yarn thereon. The sheath is supported exclusively by the spindle blade 21 so that lateral forces on the sheath are resisted only by the radial bearing 26 and footstep bearing 27. Slight unbalance or eccentricity of the yarn package on the spindle creates a centrifugal force on the upper end of the spindle tending to rock or pivot the spindle blade 21 in the upper radial bearing 26.

With the upper bearing 26 acting as a fulcrum or pivot point for the spindle blade 21, the lower tapered end 23 of the blade is permitted to move laterally off the axis of the bolster case 11 in response to centrifugal forces acting on the members above the radial bearing 26. In a known manner, lateral movement of the footstep bearing 27 is resisted and damped by viscous forces in the oil in the capillary spaces 37 between the coils of the spring 36 when such oil is displaced from the side of the spring towards which the footstep bearing 27 moves. Additionally, lateral movement of the footstep bearing 27 from its illustrated centered position is resisted by bending resistance of the resilient centering spring or pin 71 which continually biases the bearing to the centered position.

Because the centering pin is fixedly secured to both the plug 53 and footstep bearing 27 relative rotation between them is limited by the spring action of pin 71 in torsion. Also, because of the clearance between the footstep bearing 27 and spacer 78, the bearing has a certain amount of vertical resistance. In combination, the centering spring 71 and damping spring 36 permit the footstep bearing 27 to controllably yield to dynamic vibrational forces on the spindle to thereby minimize stresses in various critical parts such as the radial bearing 26, spindle blade 21 and footstep bearing 27. Furthermore, lateral displacement of .the upper end or sheath portion of the spindle is limited to a reasonably small amplitude for maximum use of available winding space.

Referring now to FIG. 3, there is shown a second embodiment of the invention in which the centering spring means is provided in a modified form. It will be understood that the portion of the bolster assembly not illustrated in FIG. 3 is substantially the same as that described above with reference to FIGS. 1 and 2. In this embodiment the bolster case and damping spring are given the previously used numeral designations l1 and 36, respectively. A footstep bearing 86 includes a tapered bore section 87 and a conical bearing seat 88 substantially identical to the corresponding surfaces 41 and 43 of the first embodiment. At the opposite or lower end 89 of the footstep bearing 86 there is formed a conical recess 91 concentric with an axial hole 92. Spring centering means in the form of a helical coil 96 resiliently biases the footstep bearing 86 to the illustrated centered condition in the bolster case 11. Preferably, the coil 96 is formed of round wire stock. An axially extending tang 97 of the spring 96 is press fitted into the axial hole 92 of the footstep bearing 86.

An end wall or plug 98 is retained in the counterbore 51 of the bolster case 11, again, by spin rolling the edge 54 against the plug. An elastomeric O-ring 99 seals the plug 98 in the bore 51 to prevent leakage from the case 11. A conical recess 103 is formed in the end plug 98 concentrically with an axial hole 104 therein. A tang 106 of the centering spring 96 is retained in this hole 104 with a press fit. The conical recesses 91 and 103 in the bearing 86 and plug 98 facilitate assembly of the pin 71 to improve the permanency of the assembly of the spring 96, bearing 86 and plug 98.

While not shown, a suitable bushing such as the bushing 75 illustrated in the first embodiment and a suitable bore in the bearing 86 may be provided to additionally improve the connection between the tank 97 and bearing. By selection of a suitable number of coils 108 and wire diameter of the centering spring 96 a satisfactory stiffness or resilience may be provided to bias the footstep bearing to the illustrated centered position. Further, the coils 108 are wound close enough with respect to each other so that when they are subjected to an unusually high axial compressive load they abut one another to form a rigid spacer thereby limiting downward movement of the footstep bearng 86 and preventing plastic deformation of the spring 96. Under normal axial operating loads, the coils- 108 are stiff enough to remain out of contact with one another and thus avoid friction between themselves when they shift laterally with the footstep bearing 86.

FIG. 4 illustrates a third embodiment of the invention wherein a footstep bearing centering spring 111 is specially formed to provide desired deflection rate characteristics. As above, members having the same structure as in the'previously described embodiments are designated with the same numerals. In this embodiment, the centering spring 111 is formed of, preferably, round wire with a single bent portion or bend 112 at its midportion and coaxial ends 113 and 114. The bent portion 112, as illustrated, lies in a plane of the drawing. Each end 113 and 114 is press fitted into the associated parts 53 and 75. As discussed and illustrated in FIGS. 1 and 2, these ends 113 and 114 may be knurled to improve the permanency of the assembly of the parts. The convoluted configuration of the spring 111 results in a spring or deflection rate somewhat less than that which results from a straight pin of the same diameter, such as that shownin F IGS. 1 and 2. Like the first embodiment, the tubular spacer 78 is dimensioned to limit axial movement of the footstep bearing 27 towards the end plug 53 to prevent plastic deformation of the spring In all of the illustrated embodiments, the centering springs 71, 76, and 111, being securely anchored to the associated end wall or plug 53 or 98, and footstep bearing 27 or 86, prevent rotation of the footstep bearing relative to the end wall. Further, the centering springs 71, 96 and 111 prevent their associated footstep bearings from being pulled upwardly out of the damping spring 36 in such cases as when a suction is formed on a bearing surface 43 or 87 upon removal of the spindle blade .21.

While preferred embodiments of the invention have been shown and described in detail, it is understood that this invention can take many other forms and embodiments, and that such forms and embodiments as may occur to those skilled in the art may be resorted to without departing from the scope of the invention as defined in the following claims.

What is claimed is: I

1. A textile spindle assembly including a tubular cylindrical bolster case having an open upper end and an end wall closing its lower end, means on the exterior of the case for mounting it to a rail, a radial spindle bearing supported on the case adjacent said open upper end, a footstep bearing axially spaced from said radial bearing in the case, an elongated damping coil spring in said case having its lower end adjacent to said case end wall and its upper end below said radial bearing, an outer coil of said damping spring engaging the inner wall of the case, said footstep bearing being laterally supported in and in engagement with the inner coil of the damping spring, a lower end of said footstep bearing being axially spaced in said damping spring from, said end wall and an upper end of said footstep bearing terminating within said damping spring, a footstep bearing locating spring in said damping coil below said footstep bearing, said locating spring rigidly engaging the lower portion of said footstep bearing atone of its ends and rigidly engaging the case end wall at the other of its ends, the rigid engagement of said spring with said end wall and said footstep bearing and the stiffness of said spring permitting said spring to laterally center said footstep bearing in said-case, to provide resilient vertical support for said footstep bearing, and to prevent rotation of said footstep bearing in said case.

2. A spindle assembly as set forth in claim 1, including spacer means below said footstep bearing for preventing said locating spring from being overstressed under excessive vertical loads.

3. A spindle assembly as set forth in claim 2, wherein said locating spring comprises a substantially straight element extending along the axis of said tubular case.

4. A spindle assembly as set forth in claim 2, wherein said locating spring comprises a helical coil symmetrically arranged with the axis of said tubular case.

5. A spindle assembly as set forth in claim 2, wherein said locating spring rigidly engages said footstep bearing through a bushing in the footstep bearing having a hardness less than that of the footstep bearing.

UNHED S'IATES PATENT OFF; (112; I CERTIFICATE OF. (IORR Patent No. 3 I I D t d March 19 1974 Inventofls) John P. Kieronski and Ray C. Johnson It is certified that error appears in the above-identified patent I and that said Letters Patent are hereby corrected as. shown below:

Column 2., Line 45, change "base" to case Column ,3, Line 54, change "usual" to unusual Column 6, Line 3, change "76" to 96 Signed and seal ed' 'this 9th day 0f Ju1y 1974.

(SEAL) Attest: H

MCCOY M. GIBSON, JR. 9 f c. MARSHALL DANN Attesting Officer Commissioner of Patents RHD/bw FORM O-1 0- USCOMM-DC 60376-P69 U.S PITIGOTFII'I 9-5 14 

1. A textile spindle assembly including a tubular cylindrical bolster case having an open upper end and an end wall closing its lower end, means on the exterior of the case for mounting it to a rail, a radial spindle bearing supported on the case adjacent said open upper end, a footstep bearing axially spaced from said radial bearing in the case, an elongated damping coil spring in said case having its lower end adjacent to said case end wall and its upper end below said radial bearing, an outer coil of said damping spring engaging the inner wall of the case, said footstep bearing being laterally supported in and in engagement with the inner coil of the damping spring, a lower end of said footstep bearing being axially spaced in said damping spring from said end wall and an upper end of said footstep bearing terminating within said damping spring, a footstep bearing locating spring in said damping coil below said footstep bearing, said locating spring rigidly engaging the lower portion of said footstep bearing at one of its ends and rigidly enGaging the case end wall at the other of its ends, the rigid engagement of said spring with said end wall and said footstep bearing and the stiffness of said spring permitting said spring to laterally center said footstep bearing in said case, to provide resilient vertical support for said footstep bearing, and to prevent rotation of said footstep bearing in said case.
 2. A spindle assembly as set forth in claim 1, including spacer means below said footstep bearing for preventing said locating spring from being overstressed under excessive vertical loads.
 3. A spindle assembly as set forth in claim 2, wherein said locating spring comprises a substantially straight element extending along the axis of said tubular case.
 4. A spindle assembly as set forth in claim 2, wherein said locating spring comprises a helical coil symmetrically arranged with the axis of said tubular case.
 5. A spindle assembly as set forth in claim 2, wherein said locating spring rigidly engages said footstep bearing through a bushing in the footstep bearing having a hardness less than that of the footstep bearing. 